Regioselectivity in the Addition of Grignard Reagents to Bis(2-benzothiazolyl) Ketone: C- vs. O-Alkylation Using Aryl Grignard Reagents
作者:Carla Boga、Gabriele Micheletti
DOI:10.1002/ejoc.201000764
日期:2010.10
The reaction between bis(2-benzothiazolyl) ketone (1) and a series of ring-substituted phenyl Grignard reagents gives, in considerable amount, the unexpected O-alkylation product derived from the attack of the Grignard reagent to the carbonyl oxygen atom, thus extending the range of rarely reported cases in which O-alkylation can occur. The expected classic 1,2-addition product and that derived from
双(2-苯并噻唑基)酮(1)与一系列环取代的苯基格氏试剂反应,得到大量意想不到的O-烷基化产物,来源于格氏试剂对羰基氧原子的攻击,因此扩大了很少报道的可能发生 O-烷基化的情况的范围。预期的经典 1,2-加成产物和衍生自 O-烷基化的产物以依赖于苯环上的取代基的相对摩尔比获得。双(2-苯并噻唑基)芳基甲醇是 1 羰基的经典 1,2-加成产物,通过替代合成路线以高产率获得,该路线允许 O-与 C-烷基化竞争施加的限制为克服。